Wireless local area networks (WLANs) enable users to access public, private, or enterprise wireless networks through wireless devices, like laptop computers. WLANs provide high-rate wireless data access in a relatively small area using a variety of wireless access protocols including the Institute for Electrical and Electronics Engineers (IEEE) 802.11 protocol. Voice over wireless local area networks (VoWLANs) build on WLANs by allowing voice enabled wireless devices like cellular phones to deliver packetized voice data over WLANs. This technology is often called Vo Wi-Fi or Wi-Fi VoIP because it uses the IEEE 802.11 protocol for wirelessly transporting voice over the WLAN and the Internet. The IEEE 802.11 protocol is, however, designed to support packetized data communication within a limited area. Voice enabled wireless devices using only the IEEE 802.11 protocol to transport voice packets are thus operable in only that limited area. And voice quality often suffers because the IEEE 802.11 protocol is optimized for wireless data communication and not voice.
Vendors of voice enabled wireless devices are currently making dual mode voice enabled wireless devices that include both the IEEE 802.11 protocol wireless capabilities in addition to standard cell phone technology. These dual mode wireless devices operate in both VoWLANs using the IEEE 802.11 protocol and in standard cellular networks.